STRUCTURE AND ACTION OF YOLCANOS. 375 



tudes, and that animals of similar forms, belonging to the 

 type, as, for instance, lions and lynxes, were capable of living; 

 in wholly different climates, such a mode of explanation would 

 at all events not admit of being extended to vegetable pro- 

 ducts. From causes developed by the physiology of vege- 

 tation, palms, bananas, and arborescent monocotyledons, are 

 unable to endure the deprivation of their appendicular organs, 

 by the northern cold ; and in the geological problem which 

 we are here considering, it seems to me a matter of difficulty 

 to admit any distinction between vegetable and animal struc- 

 tures. One and the same mode of explanation must be ap- 

 plied to both forms. 



In concluding thi& treatise, I have added some uncertain 

 ind hypothetical conjectures to the facts which have been 

 collected in widely remote regions of the earth. The philoso- 

 phical study of nature rises above the requirements of mere 

 delineation, and does not consist in the sterile accumulation of 

 isolated facts. The active and inquiring spirit of man may 

 therefore be occasionally permitted to escape from the present 

 into the domain of the past, to conjecture that which cannot 

 yet be clearly determined, and thus to revel amid the ancient 

 and ever-recurring myths of geology. 



